Bought a '71 220 in 1994 for $500. The car is long gone but the M115 engine/transmission is on it's 4th body ('71, '69, '68 and now a '72, all W114/115's) and running strong. Doesn't really count since it's not a diesel.

Bought a '73 220D in 1994 also. Paid $175 and had to put $5 in diesel and a new battery in it. Spent $10 at the car wash spraying the bird crap off it (no kidding, it had been stored in a barn with nesting hens), drove it for 8 years, gave it to my son who drove it HARD for two years and finally sold it for $2500 to a woman who speed parked a Toyota in the trunk! Damn, I miss that old beast!